Although many children acquire reading skills rapidly with some formal training, for others, learning to read is the most difficult challenges they face in the first few years at school. The reasons for these large individual differences in skill acquisition are still obscure, with the relative contribution of biological and environmental factors vigorously debated. Although it is well established that deaf individuals may experience particular difficulty learning to read, the neural basis of this phenomenon is obscure. We propose a series of integrated studies combining behavioral measures with functional magnetic resonance imaging (fMRI) to investigate the neurobiological basis of phonological basis of phonological processing and reading in deaf and hearing children. Deaf children, drawn from a group that uses ASL, will be compared to a group of hearing children matched for chronological and reading age. The results will expand our understanding of reading disability resulting from altered sensory experience. In the second phase of the study, half of the deaf children will be studied again after acquisition of another communication system, which should result in better access to the phonological code of language, Cued Speech. This communication system can be considered a signed version of spoken English and, unlike ASL, contains phonological information. By learning Cued Speech, children will gain visual access to phonetic information, providing them with the skills crucial for successful reading of English. Comparisons of brain correlates of reading after the acquisition of Cued Speech will be made with control groups of deaf children that do not learn how to utilize Cued Speech. A better understanding of how deaf individuals gain access to phonological information and are able to read more efficiently may provide new insights into the compensatory mechanisms available to compensate for the effects of reading disability may provide important new information leading to the development of more effective language instruction and intervention programs for both deaf and hearing individuals with reading disabilities.